The present invention relates to a data transmitting/receiving apparatus such as a base station, a user terminal or the like which in a wireless network system, determines depending on a signal strength of a received radio wave whether a receiving operation should be continued, and a control method thereof.
A data transmitting/receiving apparatus has heretofore been equipped with a transmitter-receiver which receives data by radio via an antenna. The transmitter-receiver converts the received radio wave to analog data and performs demodulation processing thereon.
As such a transmitter-receiver, there is known one which detects a signal strength of reception data and determines based on the signal strength whether a received radio wave corresponds to the data to be received, thereby making it possible to determine whether a receiving operation should be continued or stopped, and which allows a comparing section in the transmitter-receiver to compare the data subsequent to demodulation processing with preset data where the received radio wave is found to correspond to the data to be received from the above result of determination, thereby allowing the comparing section to determine whether the data is destined for the present apparatus.
Meanwhile, in a burst signal demodulator described in a patent document 1 (Japanese Unexamined Patent Publication No. Hei 10(1998)-243041), a timer circuit thereof is capable of outputting a counter output based on a frame signal sent from a comparison circuit and demodulation clocks sent from the demodulator to the demodulator and a UW detector to thereby suppress fluctuations in demodulated data.
In the conventional data transmitting/receiving apparatus, however, a comparing section performs comparison processing on the reception data immediately when a transmitter-receiver accepts a receiving operation instruction from a control circuit. Thus, when there is a need to allow a predetermined time to elapse from the start of a receiving operation in order to obtain accurate demodulated data upon demodulation processing of the reception data, the demodulation processing might not be performed normally. Despite the data is destined for the present apparatus, the transmitter-receiver might recognize the data as being destined for other apparatus. Thus, when the transmitter-receiver misidentifies the reception data, a reception stop is required of the control circuit, so that the data transmitting/receiving apparatus cannot perform the receiving operation normally.